Head of family, in terms of federal income tax, refers to a filing category. It is a person who is legally separated or unmarried and who is providing for a family of at least one member and has been doing that for at least half of a year.
The tax rate is lower for someone who is filing as a head of family as compared to the person who is filing as single. Head of family can also be called a primary breadwinner of a family.This is also known as filing as the head of household.